Miniaturized optical navigation systems are known in the art using primarily analog-based technology. For example, pocket-sized scanners are known in the art whose architecture comprises a photo detector array, an analog spatial image enhancement filter, and an analog correlator with off-chip bias and control. While serviceable, the accuracy of such analog systems is not optimal since so much of the algorithmic processing of the image signal (e.g. filtration, correlation) is done in the analog domain. The complementary metal oxide silicon (CMOS) technology supporting chips performing this processing cause slight imperfections and variations in the physical CMOS structure (e.g. non-linearity, device mismatches, power supply issues) to substantially affect a predictable and repeatable performance of such analog systems. As a result, the systems are not very suitable for mass manufacture.
There is therefore a need in the art to process images on-chip in the digital domain. Digitized images are susceptible to precise algorithmic computations to give predictable and reliable results, allowing accurate navigation. Such dependability would lend itself better to mass manufacture. Digital processing also facilitates tuning of algorithmic parameters to "fine-tune" or customize a design to specific applications. Such tunability is not practical in an analog domain subject to the vagaries of physical CMOS structure.